Static random access memory (SRAM) devices are electronic memory devices that store digital information or data in an arrangement of memory cells. Unlike ordinary, volatile memory devices, static memory devices retain their contents without a refresh cycle. It is interesting to note that a trickle of electrical current, such as the amount of current that would not significantly affect the battery life of a conventional battery, is enough current to maintain the contents of a memory cell of an SRAM.
NMOS and PMOS transistors are formed in SRAM devices. Typically the gates of these transistors overly a substrate and the source/drain regions of the transistors are formed in the substrate. It is necessary to provide an electrical potential to the source/region in order for the transistor to operate. In SRAM fabrication a buried contact region is formed in the substrate. A conductive layer is deposited on the buried contact region. The conductive layer is connectable to an electrical potential. Therefore in order to connect the electrical potential to the source/drain region through the buried contact region there must be an electrical connection between the buried contact region and the source/drain region. In the related art, shown in FIG. 1, the source/drain region 1 and the buried contact region 2 overlap thereby providing the electrical connection in area 3. There are several disadvantages inherent in the structure formed by this process. First the conductive layer 4 is etched to expose the substrate in order to form the source/drain region 1. Since the etch is not selective over silicon, a typical substrate material, the substrate 5 is inadvertently etched forming a small trench 6. The formation of the trench 6 necessitates careful manipulation of the process to ensure that the trench 6 does not isolate the buried contact region 2 from the source/drain region 1 or result in side effects such as junction leakage from damage in the silicon substrate. If indeed the trench isolates the two regions the substrate will provide a high resistance path between the two regions. Without proper trench control, yield problems increase and more parts fail. As in any competitive industry, there exists a need to increase yield thereby decreasing costs.